. Nitrite is a highly toxic substance and a carcinogen. Adults can be poisoned if they ingest 0.2-0.5g, and die if they ingest 3.0g. The main features of poisoning are: blue lips, tongue tips and fingertips, and blue conjunctiva, face and whole body skin in severe cases. Dizziness, headache, fatigue, rapid heartbeat or irritability, dyspnea, nausea, vomiting, diarrhea, coma, convulsions, incontinence, and death due to respiratory failure.